SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbcba2b7b9aa35217548abb1cec491851d00069857990894ece6f480761615f7' 
  AND token = '+xKusNiAfAcblOcir5FDv0Y5EzLqlpEqnActv7CgtCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}